Description
OBD-II Trouble Code Description for P0121 Hummer
Throttle/Pedal Position Sensor/Switch “A” Circuit Range/Performance
What does this mean?
OBD2 Code P0121 Hummer definition:
The Throttle position sensor is a potentiometer that measures the amount of throttle opening. As the throttle is opened, the reading (measured in volts) goes up. The powertrain control module (PCM) supplies a 5 Volt reference signal to the throttle position sensor (TPS) and usually a ground also. A general measurement is: at idle = .5 Volts; full throttle = 4.5 Volts. If the PCM detects that the throttle angle is greater or less than it should be for a specific RPM, it will set this code.
Symptoms
Possible sumptoms of OBD code P0121 Hummer
Symptoms of a P0121 Hummer trouble code could include: Malfunction Indicator Lamp (MIL) illumination (Check Engine Light or Service Engine Soon light) Intermittent stumble on acceleration or deceleration Blows black smoke on acceleration No start
Causes
Possible causes of OBD code P0121 Hummer
A code P0121 Hummer may mean that one or more of the following has happened: TPS has intermittent open or short internally Harness is rubbing and causing an open or short in the wiring Bad connection at the TPS Bad PCM (less likely) Water or corrosion in connector or sensor
Possible Solutions
1. If you have access to a scan tool, see what the idle and WOT (wide open throttle) readings are for the TPS. Check if they’re close to the specifications mentioned above. If not, then replace the TPS and re-check. 2. Check for an intermittent open or short in the TPS signal. To do that, you can’t use a scan tool. You’ll need an oscilliscope. The reason is because scan tools take samplings of many different readings over just one or two data lines and can miss an intermittent drop out. Hook up your oscilliscope and watch the signal. It should sweep up and down smoothly with no drop outs or spikes. 3. If no problems were noticed, perform a wiggle test. Do this by wiggling the connector and harness while watching the pattern. Does it drop out? If so, replace TPS and re-check. 4. If you have no TPS signal, check for 5 Volt reference at the connector. If it’s present, check the ground circuit for open or shorts. 5. Make sure the signal circuit isn’t 12V. It should never have battery voltage. If it does, trace circuit for short to voltage and repair. 6. Look for any water in the connector and replace TPS as necessary.
The OBD2 Code Information Be Applicable For Hummer:
2009 Hummer H3T Alpha,2008 Hummer HX Concept,2008 Hummer H3 Wagon Concept,2008 Hummer H3 Alpha,2008 Hummer H2,2007 Hummer H3 Open Top,2007 Hummer H3X,2007 Hummer H3R Off Road Concept,2007 Hummer H2 Safari Concept,2006 Hummer H3,2006 Hummer H2 SUT Limited Edition,2006 Hummer H1 Alpha,2005 Hummer H3 Street,2005 Hummer H2 SUT,2004 Hummer H2 SUT Concept,2004 Hummer H2H Hydrogen Concept,2004 Hummer H2,2004 Hummer H1,2003 Hummer Humvee Military Vehicle,2003 Hummer H3T Concept,2003 Hummer H2 with GM Accessories,2003 Hummer H2 SUV,2003 Hummer H2 SUT Dirt Sport Concept,2003 Hummer H1,2003 Hummer Bike,2002 Hummer H2 SUV Concept,2002 Hummer H1 10th Anniversary Edition,2002 Hummer H1,2001 Hummer H1 Alpha Concept
Note:
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